X1+x2=3 U x1*x2=-10
1/x1+1/x2=(x2+x1)/(x1x2)=-3/10=-0,3
x1/x2+x2/x1=(x1²+x2²)/(x1+x2)=[(x1+x2)²-2x1x2]/(x1x2)=
=(9+20)/(-10)=-2,9
<span> (√3+i)^3 =</span>√3³+3(√3)²i+3√3(i)²+i³=3√3+9i-3√3-i=8i
Возведём в квадрат обе части равенства
(х+ 1/х)² = 2.5²
х² + 2 * х * 1/х +(1/х)² = 6.25
х² + 2 + (1/х)² = 6.25
х² + (1/х)² = 6.25 - 2
х² +(1/х)² = 4.25
Ответ: 4.25
X^(log(3) x - 2) = 27, ОДЗ: x > 0
x^(log(3) x - 2) = x^(log(x) 27
x^(log(3) x - 2) = x^(3log(x) 3
x^(log(3) x - 2) = (3log(3) 3) / x^ (log(3) x)
log^2(3) x - 2*log(3) x - 3 = 0
1) log(3) x = -1
x = 3^(-1)
x1 = - 1/3 не удовлетворяет ОДЗ: x > 0
2) log(3) x = 3
x = 3^3
x2 = 27
1).6xy+15yz=3y(2x+5z); 2).5y-10xy=5y(1-2x); 3). -y^5-y^3+y=-y(y^4+y^2-1).